/Engine/Source/Runtime/Engine/Public/Animation/AnimCurveTypes.h
Accumulate the input curve with input Weight
template<typename OtherAllocator, typename OtherElementType> void Accumulate ( const [TBaseBlendedCurve](API\Runtime\Engine\Animation\TBaseBlendedCurve)< OtherAllocator, OtherElementType > & AdditiveCurve, float Weight )